Catálogo de publicaciones - revistas

<jats:title>Driving strontium titanate ferroelectric</jats:title> <jats:p> Hidden phases are metastable collective states of matter that are typically not accessible on equilibrium phase diagrams. Nova <jats:italic>et al.</jats:italic> used infrared pulses to excite higher-frequency lattice modes that drive the crystal into a metastable ferroelectric phase, a phase that can persist for many hours. X. Li <jats:italic>et al.</jats:italic> used terahertz fields to drive the soft mode that moves the ions in the crystal into the positions they occupy in the new phase. The ferroelectric phase in this case was transient, lasting on the order of 10 picoseconds. Because these hidden phases can host exotic properties in otherwise conventional materials, the accessibility to and control of such hidden phases may broaden potential functionality and applications. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1075" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw4911">1075</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1079" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw4913">1079</jats:related-article> </jats:p>

<jats:title>Driving strontium titanate ferroelectric</jats:title> <jats:p> Hidden phases are metastable collective states of matter that are typically not accessible on equilibrium phase diagrams. Nova <jats:italic>et al.</jats:italic> used infrared pulses to excite higher-frequency lattice modes that drive the crystal into a metastable ferroelectric phase, a phase that can persist for many hours. X. Li <jats:italic>et al.</jats:italic> used terahertz fields to drive the soft mode that moves the ions in the crystal into the positions they occupy in the new phase. The ferroelectric phase in this case was transient, lasting on the order of 10 picoseconds. Because these hidden phases can host exotic properties in otherwise conventional materials, the accessibility to and control of such hidden phases may broaden potential functionality and applications. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1075" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw4911">1075</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1079" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw4913">1079</jats:related-article> </jats:p>

<jats:title>Longer ripples make better memories</jats:title> <jats:p> Sharp wave ripples in the hippocampus are thought to play a role in memory formation and action planning. Fernández-Ruiz <jats:italic>et al.</jats:italic> used multisite electrophysiological recordings combined with optogenetic activation of hippocampal pyramidal neurons in rats performing learning tasks. Learning and correct recall in spatial memory tasks were associated with extended sharp wave ripples. Artificially prolonging these ripples improved working memory performance, whereas aborting the late part of ripples decreased performance. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1082" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aax0758">1082</jats:related-article> </jats:p>

<jats:title>Dynamic metasurfaces</jats:title> <jats:p> Nanostructured metasurfaces can function as many passive optical elements. Now, S.-Q. Li <jats:italic>et al.</jats:italic> demonstrate that metasurfaces can be combined with liquid crystals to provide active control over light beams. With a view toward developing near-eye augmented reality display technology, they combined a dielectric metasurface with a liquid crystal layer to produce a tiny spatial light modulator. The results present a path for the development of dynamic metasurfaces as a platform for miniaturized optical technology with advanced time-dependent functionality. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1087" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw6747">1087</jats:related-article> </jats:p>

<jats:title> Three's a charm for iron and CO <jats:sub>2</jats:sub> </jats:title> <jats:p> Large-scale electrochemical reduction of CO <jats:sub>2</jats:sub> to CO could be a promising first step in sustainable conversion of the greenhouse gas to commodity chemicals. Currently, gold and silver are the most active catalysts for this process, whereas more abundant, less expensive metals tend to require impractically high potentials. Jun Gu <jats:italic>et al.</jats:italic> now report an iron catalyst with activity equaling or exceeding that of the precious metals. The key proved to be stabilization of the dispersed single iron ions in the +3 oxidation state. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1091" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw7515">1091</jats:related-article> </jats:p>

<jats:title>How to make almonds palatable</jats:title> <jats:p> The domesticated almond tree has been feeding humans for millennia. Derivation from the wild, bitter, and toxic almond required loss of the cyanogenic diglucoside amygdalin. Sánchez-Pérez <jats:italic>et al.</jats:italic> sequenced the almond genome and analyzed the genomic region responsible for this shift. The key change turned out to be a point mutation in a transcription factor that regulates production of P450 monooxygenases in the biosynthetic pathway for the toxic compound. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1095" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aav8197">1095</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>